Kaby Lake On Linux Plays Much Better With CPUFreq Than P-State

The Linux 4.10 kernel as found via the Ubuntu Mainline PPA and similarly configured via their stock kernel ends up using the P-State driver on modern Intel CPUs with the powersave governor. P-State is supposed to offer the best power/performance over the generic CPUFreq scaling driver, but we've seen that's not often the case. Intel's own Clear Linux distribution even uses CPUFreq performance over P-State. So while all these older Intel CPUs for the comparison were on P-State powersave, I decided to do another run when switching to CPUFreq with the performance governor.

Sure enough, switching away from P-State as the default behavior and instead using CPUFreq with the performance governor leads to better performance. Though with a turbo boost up to 4.2GHz, the gains should be a bit better than what we're seeing. Anyhow, I am still working on some other tuning tests and experimenting with different options for finding out the ideal Kaby Lake Linux configuration. Just wanted to pass along these early numbers for those that may have picked up a Kabylake CPU and are encountering similar slower performance than anticipated. This also makes for a good forum discussion again over the state of P-State; more tests coming plus of other governor options on both CPUFreq and PState.